This invention relates to x-ray film cassettes and cassette holders and covers of the type to be used with x-ray equipment, wherein film is encased in a film cassette and the film and the cassette are exposed to x-rays, as when forming images of the skeletal portions of the human body, etc. More particularly, the invention relates to the marking of x-ray film with the letters L or R as the film is exposed with x-rays so as to indicate that the image shown on the film is of the left or right portion of the body.
When x-ray images are made of the human body, it is highly desirable to mark the x-ray film with the letters L or R so that when the physician inspects the developed x-ray film, the physician is certain as to which limb or portion of the body is being observed. In the past, x-ray impermeable letters have been physically attached to film cassettes by applying adhesive tape about lead letters and attaching the adhesive to the exterior surface of the x-ray permeable sheet of the cassette to fasten the letters to the cassette. While this procedure causes the R or L indicia to be imposed on the x-ray film, the procedure is not always convenient or successful. For example, the R and L letters are not always applied to the same portion of the film cassette and therefore the images left by the letters on the film appear in random locations on the film. In some instances, the lead letters are dislodged from the cassette before the film is exposed, so that there is no indicia image on the exposed film. In some instances the lead letters are dislodged and moved toward the center of the cassette during the procedure of making the x-ray image, and the images of the indicia appears near the center of the developed film. In other instances the x-ray technician may simply forget to apply the L and R letters to the cassette.